For much of the past decade, the season finale at Camden Yards has been a simple affair, several thousand fans politely ushering in autumn with another lost season completed.

On Wednesday, in the Orioles' 4-3, come-from-behind, no-way-that-happened win over the Boston Red Sox, the vibe at Camden Yards was different -- tense moments, jump-to-your-feet excitement, a pennant-race atmosphere for a cellar-dwelling club that began the night 29 games out of first place.

The Orioles' season ended with walk-off single by Robert Andino against Boston Red Sox closer Jonathan Papelbon, who struck out his first two batters before giving up the 3-2 lead on consecutive doubles by Chris Davis and Nolan Reimold.

Andino then laced a diving liner to left field that Carl Crawford couldn't catch while sliding. Reimold chugged around third and scored the winning run -- which moments later culminated in the end of the Red Sox's season, too.

"End of season like this -- [to] make Boston go home sad, crying -- I'll take it all day," Andino said.

Far from a playoff team, the Orioles finished with a 69-93 record but won 11 of their final 16 games, all against postseason contenders. None was as electric as Wednesday's finale, which didn't end until midnight and went down to the final pitch.

"It was exciting," Reimold said. "We battled to the end, and we came out on top this time. We weren't playing for the playoffs, but we were playing for pride, and we showed it tonight."

The rare pennant fever was brought to Baltimore courtesy of the Red Sox, who entered Wednesday tied for the American League wild-card playoff berth with the Rays.

The announced 29,749 at Camden Yards -- which included the usual healthy mix of Red Sox Nation -- bought into the fervor despite a torrential downpour. The fans knew a win against Boston would send their divisional foe either home for the fall or to a one-game playoff.

For the Red Sox, Thursday will now be a day of blame for the worst September collapse in baseball history.

"I can't believe what Boston must be going through emotionally right now," Orioles manager Buck Showalter said. "We understand that there's another side to this.

"Baseball is a cruel game."

For the Orioles, Thursday represents immediate uncertainty -- with president of baseball operations Andy MacPhail expected to meet in the afternoon with club owner Peter Angelos and Showalter.

MacPhail, whose contract expires at the end of October, is expected to voluntarily step down from his post, and Showalter is seemingly 50-50 on whether he wants to stay in the dugout or move up to the front office. Those decisions could be hashed out Thursday.

For the final frenzied hours of the Orioles' season Wednesday, however, the drama played out on the field as the sides traded leads and suffered through a rain delay that extended the seventh-inning stretch into a 1 hour, 26 minute catnap.

The Red Sox (90-72) scored first in the second inning on a single by Dustin Pedroia. The Orioles jumped ahead in the third on J.J. Hardy's two-run homer, his 30th of the season. Hardy joined Mark Reynolds as the first Orioles teammates to hit 30 or more home runs in the season since Brady Anderson and Rafael Palmeiro did it in 1996.

Boston tied it in the fourth when Alfredo Simon balked in a run. The Red Sox took the lead in the fifth on a solo homer by Pedroia, his 21st of the season.

A batter later, Simon was chased, ending his bizarre season with a shaky 4 1/3 innings of three-run ball. He allowed six hits and three walks and pushed his season ERA to 4.90.

It capped Simon's strange year, which began with nearly two months in a Dominican Republic prison as the lead suspect in the shooting death of his cousin Jan. 1. He hopes to be cleared of any wrongdoing during a hearing Oct. 18 in the Dominican.

Simon drew a tough assignment Wednesday, facing the desperate Red Sox and opposing Boston starter Jon Lester, who was 14-0 in 17 starts against the Orioles in his career -- the longest such active streak by one pitcher against one opponent in all of baseball.

The Orioles had their chances against Lester, including in the fifth, when Reynolds raced home from third on a grounder to a drawn-in infield and was thrown out at the plate. In the sixth, Lester walked three batters but didn't allow a run thanks to a strikeout and a great double play on a grounder up the middle by Vladimir Guerrero. Shortstop Marco Scutaro grabbed the ball and tossed it with his glove to Pedroia, who spun and threw to first to get the slow-footed Guerrero.

Lester, who was pitching on three days' rest, didn't return after the delay. He allowed two runs on four hits and four walks while striking out five in six innings.

On a night filled with close plays -- the Orioles prevented a run in the eighth when Jones, Hardy and Wieters combined for a perfect relay and putout at the plate -- the Orioles mostly failed to score against the Red Sox bullpen.

Papelbon (4-1) attempted to close it out, but the Orioles are the ones that will head into the offseason feeling a little better about the end of the 2011 baseball season.

"I think that our finish overall is encouraging," said closer Jim Johnson (6-5), "though I know we did this last year. A day like today just shows you how crazy baseball can be. They absolutely dominated us for a long time, so this is a little justification at the end of the year."

Said Showalter: "That's the only time I haven't talked to the team after the last game of the season. Pretty tough to top that. Not much to say. I'm just so proud of them. I'm also proud of our fans."